21661226242541 has 8 divisors (see below), whose sum is σ = 22939993125504. Its totient is φ = 20382967926720.

The previous prime is 21661226242517. The next prime is 21661226242549. The reversal of 21661226242541 is 14524262216612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21661226242541 - 2¹⁰ = 21661226241517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21661226242492 and 21661226242501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661226242549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127054085 + ... + 127224458.

It is an arithmetic number, because the mean of its divisors is an integer number (2867499140688).

Almost surely, 2^{21661226242541} is an apocalyptic number.

It is an amenable number.

21661226242541 is a deficient number, since it is larger than the sum of its proper divisors (1278766882963).

21661226242541 is a wasteful number, since it uses less digits than its factorization.

21661226242541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254283571.

The product of its digits is 552960, while the sum is 44.

The spelling of 21661226242541 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred twenty-six million, two hundred forty-two thousand, five hundred forty-one".